Front End Device

1. A front end device that is connected between a transmission-reception apparatus and an antenna and that performs certain processing on a high-frequency signal, the front end device comprising: a first high-frequency device including a first interface unit; and a second high-frequency device including a second interface unit and a second high-frequency device processor; wherein the first interface unit is connected to the transmission-reception apparatus and the second interface unit, receives only a serial signal and no parallel signal from the transmission-reception apparatus, converts the serial signal into a parallel signal, and transmits the parallel signal to the second interface unit; the second interface unit receives the parallel signal only from the first interface unit and supplies the parallel signal to the second high-frequency device processor; and the second high-frequency device processor is connected between the transmission-reception apparatus and the antenna and performs processing on the high-frequency signal based on the parallel signal.

2. The front end device according to claim 1 , wherein the first high-frequency device includes a first high-frequency device processor; and the first high-frequency device processor is connected between the transmission-reception apparatus and the antenna and performs processing on the high-frequency signal under control of the first interface unit based on the serial signal.

3. The front end device according to claim 2 , wherein the first high-frequency device processor and the second high-frequency device processor is one of a switch circuit, a low noise amplifier circuit, or a power amplifier.

4. The front end device according to claim 2 , wherein the first high-frequency processor is connected between an RFIC and an antenna.

5. The front end device according to claim 2 , wherein the first interface unit is connected to a serial interface unit via three signal lines.

6. The front end device according to claim 2 , wherein the first interface unit is connected to a first parallel interface unit via three signal lines, is connected to a second parallel interface unit via one signal line, and is connected to a third parallel interface unit via two signal lines.

7. The front end device according to claim 1 , wherein the front end device includes a plurality of second high-frequency devices.

8. The front end device according to claim 1 , wherein the front end device includes a plurality of pairs of the first high-frequency device and the second high-frequency device.

9. The front end device according to claim 8 , wherein each pair of the first high-frequency device and the second high-frequency device includes one IC package.

10. The front end device according to claim 1 , wherein the first or second high-frequency device processor is a switch circuit that switches a high-frequency signal path connecting the transmission-reception apparatus to the antenna.

11. The front end device according to claim 1 , wherein the first or second high-frequency device processor is an amplifier circuit that amplifies the high-frequency signal transmitted from or received with the antenna based on the parallel signal.

12. The front end device according to claim 1 , wherein the first interface unit is connected to a serial interface unit in an via three signal lines for a data signal, a clock signal, and power.

13. The front end device according to claim 1 , wherein the first interface unit is connected to a first parallel interface unit via two signal lines and is connected to a second parallel interface unit.

14. The front end device according to claim 1 , wherein the transmission-reception apparatus is one of an RFIC, a semiconductor element, and a baseband integrated circuit.